This invention relates to generator rotors and, more specifically, to the blocking of end arc portions of the field windings of generator rotors.
Generator fields with C-coil windings in tapered rotor slots have special blocking requirements in the end arc region of the windings. The space between end arcs in adjacent coils is larger for turns located closer to the axis of rotation of the rotor than it is for turns located closer to the peripheral surface of the rotor. Normal assembly procedure calls for location of spacer blocks between coils after the coils have been wound into the field. For windings located in parallel sided rotor slots, such blocks have parallel faces. This allows the blocks to be assembled after all of the coils have been wound. However, for designs with turns located in tapered slots, the blocks need to be wider at the radially inboard end than at the radially outboard opening where they are inserted. These tapered blocks must be assembled against each coil stack as the field is wound. This arrangement, however, does not allow for any adjustment after winding, and does not allow the blocks to be removed without first disassembling entire coils from the rotor.